Controlling apparatus



' Nov. 13, 1934.

R. D. MODILL- 1,980,816

CONTROLLING APPARATUS Filed Dec. 15, 1952 I g I INVENT\0R A TTORNEYSPatented Nov. 13, 1934 UNITED STATES PATENT OFFICE 8 Claims.

the description of several practical embodiments thereof illustrated inthe accompanying drawing, in which;

Figure 1 is a diagrammatic representation of one form of the apparatusarranged to operate a relay upon the presence or absence of .a body in aparticular location;

Figure 2 is a fragmentary diagrammatic illustration of the apparatus ofFigure 1 arranged for use in measuring objects;

Figure 3 is another modification of the apparatus of Figure 1 showingthe manner in which the apparatus may be used to operate a devicedesigned, for a current of a different frequency than that available;and

Figure 4 is another modification of the apparatus showing "a manner ofits application to the. coating 'or similar treatment of objects beingpassed continuously by it.

Referring first to the arrangement of Figure 85 1, a source of currentis illustrated at 1, this being conveniently an alternating currentgenerator such as supplies 110 volt, 60 cycle, A. C. for theillumination of; buildings and the like,

- and may be considered as a central power plant, remote from theapparatus, and may be groundd, as indicated at 2.

Current passes through conductors 3 and 4 to a coil 5 at the apparatus.This coil constitutes in effect the primary of a transformer having a45, core 6 The transformer has two secondary coils '7 and 8, the formerof which is connected by conductors 9 to the terminals of a filament 10of a thermionic valve or tube, ,such for instance as the mercury vaporrectifier now known as the thyratron, and=to supply the current forheating this filament.

From a central tap on coil 7 to a similar tap on coil 8 extends aconductor 11. Connected to one end of coil 8 is a conductor 12 whichextends 66 to one end of a potentiometer or similar resist Thisinvention relates to electrical controlling ance element 13, the otherend of which isconnected by a conductor 14 to the central tap of coil 8.From the adjustable contact of the potentiometer a conductor 15 extendsto a variable condenser 16, and a conductor 1'7 connects the condenserto the grid 18 of the tube.

Connected to the other end of coil 8 is a conductor 19 which includes acoil 20 and is connected to the plate 21 of the tube. The coil 20 isshown as provided with an armature 22 arranged to complete a circuit bybeing moved against contacts 23 from which conductors 24 pass to someelectrical device (not shown) which it is desired shall be controlled.

A conductor 25 extends from conductor 1'1 and is provided at its endwith a conducting plate 26 or the like.

If, with the apparatus just described, current is supplied to primarycoil 5 by generator 1, it will induce currents in the secondary coils 7and 8, the current in the former heating the filament 10. By properadjustment of the potentiometer 13 and condenser 16, any desired biasmay be impressed upon the grid of the tube, and by this meanscurrent maybe prevented from passing through coil 20.

If, now,-the charge which accumulates upon the plate of the condenserconnected to conductor 1'1 be allowed to discharge, as by the approachof some object to plate 26, the grid bias as will disappear, currentwill flow through conductor 19, causing coil 20 to function, and raisearmature 22, breaking the circuit between conductors 24, and thusoperating whatever device is in the circuit of these conductors.

In the apparatus of Figure 2, two mechanical contacts 27 and 28 havebeen provided, the former of which is in fixed position, and the latterof which is urged toward the former by a spring 29. The movable contact28 is mechanically con- 95 nected to one of the plates of condenser 16.If

an object is placed between the two mechanical contacts, it will movethis condenser plate relative the other plate, varying the grid bias inproportion to the width of the object, and thus we control theoperationof armature 22. By adlusting the apparatus to operate the relay when themechanical contacts are at a known distance apart, objects may beaccurately and rapidly measured by being passed between the two me- 1 5chanical contacts. a

In Figure 3, the circuit is substantially the same as that shown inFigure 1, excepting that one of the contacts 23' has been connected toco ductor 1'1, and the other 23" has been con- 11 nected to a ground 30.In addition, a motor or other device which it is desired to operate hasbeen connected in parallel with coil 20.

This arrangement is particularly advantageous where the device 31 isdesigned to ,operate upon a current of different frequency from thatsupplied by generator 1. For instance, if the generator produces 60cycle current and the motor or other device 31 is designed to operate at15 cycles, the potentiometer and condenser are adjusted so that currentwill pass through coils 20 and 8 until the grid bias has been built upby four pulsations of the 60 cycle current. Therefore, for every periodof four cycles of generator 1, one electrical impulse passes throughconductor 19 to device 31 and coil 20; thus the arma ture will be raisedand will ground conductor 17, permitting the grid bias to leak off andso starting the flow of current through coils 8 and 20, and thenallowing the armature to assume its normal position. In this manner,current is permitted to flow to the motor 31 in pulsations 4th asfrequent as that which is supplied by generator 1, and the apparatusperforms the function of an ordinary rotary converter while being farsimpler in its construction.

In Figure 4, the apparatus. is shown as arranged for sprinklingcomminuted material upon a series of objects rolling along an inclinedpath. The material is dropped upon the objects from a grater or grinder101 driven by a motor 120 which has been placed in the conductor 19,replacing coil 20 above described.

The inclined path down which the objects pass consists of two parts 102and 103 of insulating 1 material, separated by a grounded metallic plateor the like 104.

The plate 26 has beenreplaced by a brush-like conducting element 126having depending extremely flexible filaments 126a, and is connected tothe conductor 25. As the objects pass between filaments 126a and plate104, they act as the dialectric of a condenser of which plate 104 andfilaments 126a are the plates, so that the grid bias is maintained at apoint where it permits current to flow to operate the motor 120, and aslong as a continuous stream of objects pass between the plate andfilaments, the motor continues to operate. Whenthe objects ceaseto'pass, the grid bias builds up to a point where it prevents furtheroperation of the motor, and so prevents wasting of the material suppliedby device 101.

While I have described the illustrated embodiments of my invention insome particularity, obviously many other embodiments will readily ocourto those skilled in this art, and I do not therefore limit myself to theprecise details shown and described herein, but claim as my inventionall embodiments, variations and modifications com ing withinthe scope ofthe subjoined claims.

I claim:

1. Electrical apparatus comprising a source of alternating current, athermionic valve, transforming means supplying current to the grid andplate of said valve, regulating means controlling the current suppliedto said grid, capacitative means controlling the potential of thecurrent supplied 'to said grid, capacitative means controlling thepotential of the current supplied to said grid and arranged to have itscapacity varied by an extraneous object.

2. Electrical apparatus comprising a source of alternating current, athermionic valve, transforming'means supplying current to the filamentof said valve, transforming means supplying current to the grid andplate of said valve, regulating means controlling the current suppliedto said grid, capacitative means controlling the potential of thecurrent supplied to said grid, and arranged to have its capacity variedby an extraneous object, and an electrical device in circuit with saidplate.

3. Electrical apparatus comprising a source of alternating electriccurrent, a transformer the primary of which is connected to said sourceand having two secondaries, a thermionic valve the filament of which isconnected across one of said secondaries, connections from the, othersecondary to the grid and plate of said valve, a condenser in theconnection betweenthe second secondary and the grid of said valve, andmeans varying the capacity of said condenser'and arranged to be actuatedby an extraneous object.

4. Electrical apparatus comprising a source of alternating electriccurrent, a transformer the primary of which is connected to said sourceand having two secondaries, a thermionic valve the filament of which isconnected across one of said secondaries, connections from'theothersecondary to the grid and plate of said valve, a condenser in theconnection between the second secondary and the grid ,of said valve, andmeans moving one of the plates of said condenser to vary the capacity ofsaid condenser, said movement being controlled by an extraneous object.

5. Electrical apparatus comprising a source of alternating electriccurrent, a'transformer the primary of which is connected to said sourceand having two secondaries, a thermionic valve the filament of which isconnected across'one of said secondaries, connections from the othersecondary to the grid and plate of said valve, a condenser in theconnection between the second secondary and the grid of said valve, astationary mechanical contact, a movable mechanical contact connected toone of the plates of denser to move therewith, and resii urging saidcontacts toward each 6. A circuit comprising a source 0 electricalenergy, a transformer 11 mary connected to said source, and t aries, athermionic valve having its filament connected to one of saidsecondaries, a resistance element connected in parallel with a portionof the second secondary, an adjustable connection from said resistanceelement including a variable condenser and connected to' the grid ofsaid valve, and a connection from one end of the second secondary to theplate of said valve including a device to be actuated, by currentpassing through said connection.

7. A circuit comprising a source of alternating electrical energy, atransformer having a primary connected to said source and twosecondaries, a thermionic valve having its filament connected to one ofsaid secondaries, a resistance element connected in parallel with aportion of the second secondary, an adjustable connection from saidresistanceelement including a variable condenser and connected to thegrid of said valve, a connection. from one end of the second secondaryto the plate of said valve including a device to be actuated by currentpassing through. said connection, and means for conducting current fromthe grid of said valve.

8. A circuit comprising a source of alternating electrical energy, atransformer having a primary connected to said source and twosecondaries, a thermionic valve having its filament condevice to beactuated by current passing through said connection, means forconducting current from the grid of said valve, and asecond electricaldevice connected in parallel with the first mentioned electrical device.

- REX D. McDILL.

DISQtAIMEFl -"'1,98 0,8'1 6.'-'--Rez D. McDz'll, Em Oleve1and,-'Ohiof.'November 13 1934. Disclaimer atont dated the patented ConnonniuofiArium'ms. January 9; 37 18 H 31) enters this disclaimer t claim g l 4 dI l F wm8$ 1987.1 f w P t.

